Line a 24 hole mini muffin tin with mini muffin liners/mini cupcake liners.
Combine chopped pretzels & peanuts, set aside.
In a medium saucepan, heat chocolate over low heat for about 2 mins, or until just melted.
Add peanut butter to chocolate, mixing to melt until smooth & combined.
Pour chocolate mixture into a heatproof jug, then pour chocolate evenly between muffin tin holes.
Sprinkle the top of each chocolate cup with peanut & pretzel mixture - pressing down slightly if needed (see note).
Refrigerate for 1 ½ hours or until set, serve cold.